3- And 5-aryl triazole derivatives have been reported in the prior art to have a wide variety of pharmacological activities. 5-Aryl-2,4-dialkyl-3H-1,2,4-triazole-3-thiones, for example, are known to have activity against depression, as claimed in U.S. Pat. No. 4,775,688, and U.S. Pat. No. 4,775,689, against thrombocytosis, as claimed in U.S. Pat. No. 4,847,276, against the symptoms of Wernicke-Korsakoff syndrome, as claimed in U.S. Pat. No. 5,100,906, against Alzheimer's disease, as claimed in U.S. Pat. No. 5,236,942,and in enhancement of memory and cognition, as claimed in U.S. Pat. No. 5,331,002. The use of 5-phenyl-1,2,4-triazole-3-thione as an antisecretory agent is disclosed U.S. Pat. No. 4,230,715. 5-Aryl-1,2,4-triazol-3-one derivatives are known to have activity against seizure disorders, as claimed in U.S. Pat. No. 4,966,909, and U.S. Pat. No. 4,946,856, and for treatment of neurodegeneration due to stroke, as claimed in pending U.S. Ser. No. 494,049. 3-Phenyl-3-alkylthio, alkenylthio, alkoxy and hydroxy-triazole derivatives are described as anticoccidial agents in Japanese Kokai 50-63119. 3-Aryl-5-alkylthio-, alkylsulfinyl- and alkylsulfonyl-4H-1,2,4-triazole derivatives are known to have activity against convulsant seizures, as claimed in U.S. Pat. No. 5,143,933, against anxiety, as claimed in U.S. Pat. No. 4,981,863, against muscle spasms and muscle tension, as claimed in U.S. Pat. No. 4,900,743, and against hyperreflexia due to spinal trauma, as claimed in U.S. Pat. No. 5,158,968. Mhasalkar, et al. (J. Med. Chem 14(3), 260-262 (1971)) evaluated a series of 3-phenyltriazoles for hypoglycemic activity and noted that the level of activity varied substantially when the substituents on the 4- and 5-positions of the triazole ring and on the benzene ring were changed.
By contrast, 3-aryltriazolium salts known to the prior art are not reported to have beneficial pharmacological activity. For example, triazolium dyes are described in German Offenlegung 3,314,659, assigned to VEB Filfabrik Wolfen, and in an article by Alberti (Ann. Chim. (Rome) (1975), 65(5-6), 305-14). Fr. 1,481,761, assigned to Badische Anilin, describes triazolium salts useful as plant protection agents. U.S. Pat. No. 4,414,221, assigned to FBC Ltd., includes triazolium salts in a genus of o-halophenyl-substituted N-heterocyclic compounds useful as pesticides against acarids and insects.